Many granular materials require processing to condition them for use. In some cases, the conditioning is primarily to breakup and eliminate any clumps or lumps that may exist in these granular materials to be certain that they are all uniformly in the granular form. In other materials, equipment of this type is used to mix or blend materials together so that additives which have been applied to the materials are thoroughly and uniformly intermixed throughout the body of the granular materials. Such additives as oil, bonding agents, coloring materials, coatings, binders, lubricants and chemicals of various types are among the materials which have to be intermixed uniformly throughout the body of these granular materials. It is important in this operation that the granular materials, after processing, are uniform in consistency whereby there will not be voids resulting from under treatment and other defects due to zones of concentration of the materials which have been mixed with the granular substances. Equipment of this type is also utilized for cooling or for drying granular materials. While the invention is particularly applicable to the preparation of molding sand for foundry use, this is but one of its many possible uses.
Heretofore, equipment designed for this purpose and particularly the equipment designed for use with foundry molding sand has utilized blenders and conditioners having paddle wheel type sand blending and mixing rotor wheels which are mounted to rotate about a horizontal axis above the surface of a material transport belt. While this arrangement does provide a degree of mixing and blending, it does not so completely and positively treat the material as to effectively aerate and mix it or to positively breakup all lumps which might exist in the material. While these blenders or conditioners which rotate about a horizontal axis, due to the lifting of the material accomplish some aeration of the material, they do not provide the positive and, in effect, high energy movement of the materials necessary to assure both blending and lump breakup. Furthermore, conventional equipment for this purpose cannot, process lumps efficiently since the rotor wheel mounted on a horizontal axis has a tendency to jam lumps downward onto the belt. Cooling is also difficult in that air cannot be easily introduced into the area where the rotor wheel and sand combine. It is the purpose of this invention to provide equipment which is dependably effective for both of these purposes and, at the same time, useful in the preparation and conditioning of a wide variety of granular type materials.